Circulation equalizer for furnace flues



Dec. 25, 1934. J, D N

CIRCULATION EQUALIZER FOR FURNACE FLUES Fild March 20, 1933 2Sheets-Sheet l *LN Inventor t]. Z. Anderson f] Home y Dec. 25, 1934. J,z. ANDERSON CIRCULATION EQUALIZER FOR FURNACE FLUES Filed March 20, 19352 Sheets-Sheet 2 Cf. Z Anderson Mum.

v fl Home y Patented Dec. 25, 1934 PATENT OFFICE.

CIRCULATION EQUALIZER FOR FURNACE FLUES James Z. Anderson, Brookfield,Ill.

, Application March 20, 1933, Serial No. 661,859

I 9 Claims.

This invention relates generally to hot air fur-- naces, andparticularly .to means -for automatically .evacuating the mother flue ofcold air when starting up a furnace and increasing the amount of warmair conveyed by the mother flue when the K sults.

furnace is in full operation.

I have discovered that cold air present in the mother flue of a hot airfurnace before the furnace has been fired and while thefurnace is heat--air or raise the temperature thereof, and where a the mother flue opensinto aclosed room or space, the cold air in the room-must be-displacedorraised in .temperature before any substantial rise in the temperaturein the room can take place. Here-v toforeexpensive mechanical means hasbeen suggested for evacuating the mother flue and the cold room of coldair to provide quickly for a free flow .of hot air from the furnace andnone .of these means have been automatic in action, andrequired.skillfuloperation to secure satisfactory re- Myinventionsupplies an entirely automatic means dependent for its actionon the state of the air in the. mother flue and the operating conditionof the furnace, and the costs of manufacturing and installing .of myinvention are so 1 smallas topresent no obstacle to its use .by everyowner of a hot 'air furnace. In the drawings: Figure l is a top planview and its motherflue showing an embodiment of my invention appliedthereto.

Figure 2 is a transverse vertical sectional view taken through Figure 1.approximately on the line 2--2.

- Figure 3 is a transverse vertical sectional view taken approximatelyon the .line 33 of Figure 2.

Figure 4 is a horizontal sectional view taken on the line 44 of Figure2.

Referring now .toFig-ure .2 of the drawings, the numeral -5 designates.a hot air furnace including the customary firepot, 6. Spacedlyenclosing the furnace 5 is the usual casing forming the air heatingchamber and having the dome 7a. The cold air to be heated is admitted tothe chamber by an intake 8. Before proceeding further, I .desire to callattention to the fact that any suitable number of mother fines 10. maylead from the dome 7a of the casing 7. :It will be understood that. thecold air entering the chamber through the intake :8 will be heated bycontact with the furnaceand will rise in the-chamber and pass out.

of a hot air-furnace.

through the outlet neck 9 to which is connected the mother flue 10. This:flue .10 includes the usual horizontal portion which extendsradiallyoutwardly from the dome 7a to convey the hot air toa room orother enclosure to be heated.

In the case of an ordinary hot air furnace it is in the horizontalportion of the mother flue 10 that the cold .air collects and opposesthe passage of hot air to the room to be heated. As the furnace is firstfired and the temperature of the air in the .air heating chamber of thefurnace gradually rises, it exerts a gradually increasing outwardpressure on thecolumn of cold air in the said horizontal portion so thatthis column of cold air begins to move outwardly, allthe time resistingthepassage of warm air through the mother flue. Since the column of coldair must gosomewhere, it ordinarilygoes into the already cold room, andthere being no escape 'forthe cold air inxthe room thus augmented,- theair in the room will notrbecome warm until its temperature has beenslowly raised by contact with such hot air as finally'enters the roomthrough the mother flue Taking advantage of thenatural tendency of coldair to sink to lower levels, I tap the said horizontal portion at aradially outward point by connecting .to one side of the lower partthereof one .endof a. pipe or flue 11 of relatively small diameter, intowhich the cold air flows downwardly of itself and in its downward flowin the pipe is assisted by the movement of the mentionedcolumn of coldair under the impetus of the developing column of hot air behind thecolumn of cold air. 4.

The auxiliary flue, which may also be referred to as an equalizing fluelies along and preferably in contact with the side of the lower part ofsaid horizontal portion of the mother flue as indicated by the numeral16. The elbow connecting the outer end of the auxiliary flue with themother flue is designated 17. The inner end of the portion 16 mergesinto a vertical portion 15 which lies along and close to or in contactwith the casing '7 and receives into its lower end a .neck 14 on the topof a box-shaped trap generally designated 12.

The trap 12 is horizontally elongated and its open inner end approachesclosely the sides of the fire pot 6, the place where the greatestheatradiation occurs. The trap is placed through asubstantially fittingsquare or other. suitable shape of opening in the side wall of thecasing '7 where it is secured by attaching means 13.

It will be obvious that the cold air movingdown wardly through the pipe11 in the manner described and while the furnace is heating up will passinto the lower part of the heating chamber through the trap, but that assoon as the furnace gets hot, the trap 12 will be heated to such anextent that warm air will develop in the trap 12 and the direction ofmovement of the cold air in the pipe 11 gradually reversed until acolumn of hot air moves upwardly in the pipe 11 and entering thehorizontal portion of the mother flue augments the column of hot airinto the mother flue in a manner to increase the volume and heatingefiect thereof.

A structural assembly of this classification costs little, is much moresatisfactory than present arrangements of this character, andeconomically afiords safety and comfort not otherwise obtainable.

A careful consideration of the foregoing description in conjunction withthe illustrative drawings will enable the reader toobtain a clearunderstanding of the purpose, features and advantages, the explicitconstruction, and the invention as hereinafter claimed.

It is to be understood that minor changes in shape, size, relativeproportions, and materials may be resorted to in practice withoutdepartment from the spirit and scope of the invention as now claimed.

I claim:

1. A circulation equalizer for a furnace flue comprising, incombination, a furnace including a fire box, a heated air trappingcasing completely surrounding said furnace and spaced therefrom, an airdelivery pipe connected to the lower portion of said casing, a heatedair conducting flue connected to the top of the casing and extendingangularly therefrom, a substantially rectangular additional air trappingbox fitted through an opening in the wall of said casing and open at itsinner end, said open inner end being located in close spaced proximityto the fire box of said furnace, the opposite end of said box extendingthrough and beyond the opening in said casing and being provided with aheated air discharge nipple, a substantially L-shaped equalizer conduitembodying a vertical branch located on the exterior of and in closeproximity to one wall of said casing and connected at its intake endwith said nipple, the horizontal branch of said pipe being located inclose spaced parallelism to said flue and having communicatingconnection with said flue at a point remote from said casing.

2. In combination, a hot air furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamber having a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue beingarranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such descending coldair into said air heating chamber whereby the cold air in saidhorizontal portion is automatically evacuated therefrom when said stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue.

3. In combination, a hot air furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamberhaving a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue beingarranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such descending coldair into'said air heating chamber whereby the cold air in saidhorizontal portion is automatically evacuated therefrom when said stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue, said lower end of saidauxiliary flue being arranged in heat exchange relation with said stovemember whereby additional heated air is produced in said lower end ofthe auxiliary flue as soon as full firing of the stove member isaccomplished, said additional heated air then rising through saidauxiliary flue and entering said mother flue so as to augment the heatedair therein.

4. In combination, a hot air furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamber having a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected-to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue beingarranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such descending coldair into said air heating chamber whereby the cold air in saidhorizontal portion is automatically evacuated therefrom when said stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue, said lower end of saidauxiliary flue being arranged in heat exchange relation with said stovemember whereby additional heated air is produced in said lower end ofthe auxiliary flue as soon as full firing of the stove member isaccomplished, said additional heated air then rising through saidauxiliary flue and entering said mother flue so as to augment the heatedair therein, said lower end of the auxiliary flue having attachedthereto, a trap comprising a box having a portion arranged through anopening in the side wall of said casing member and extending toward saidstove member, the radially inward end of said portion of the box beingclosely spaced from the side of said stove member and open to pass coldair into said chamber against the side-of said stove mem-,

means later and receive heated air from said "chamber from the hotsideof said stove member. I

5. In combination, a hotair furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamber having a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue beingarranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such descending coldair into said air heating chamber whereby the cold air in saidhorizontal portion is automatically evacuated therefrom when said stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue, said auxiliary flue having asubstantially horizontal part lying along said horizontal portion of themother flue in heat exchange relation thereto.

6. In combination, a hot air furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamber having a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue beingarranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such descending coldair into said air heating chamber whereby the cold air in saidhorizontal portion is automatically evacuated therefrom when said stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue, said auxiliary flue having asubstantially horizontal part lying along said horizontal portion of themother flue in heat exchange relation thereto, said auxiliary flue beingarranged exteriorly of said mother flue.

'7. In combination, a hot air furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamber having a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue*being arranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such de-- scending coldair into-said :air heating chamber whereby .the 'cold air insaidhorizontal portion is automatically evacuated therefromwhenzsaid stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue, said auxiliary flue having asubstantially horizontal part lying along said horizontal portion of themother flue in heat exchange relation thereto, said auxiliary fluehaving a vertical portion arranged exterior of and in heat exchangerelation to the side wall of said casing member.

8. In combination, a hot air furnace including a stove member and acasing member surrounding and enclosing said stove member and forming anair heating chamber, said chamber having a cold air intake at its lowerend and a heated air outlet at its upper end, a mother flue connected toand fed by said heated air outlet and having a substantially horizontalportion leading away from said furnace, an auxiliary flue having itsupper end connected to and communicating with the lower part of one sideof said substantially horizontal portion at a point remote from saidfurnace, the lower end of said auxiliary flue being connected to anintermediate part of one side of said casing member and communicatingwith the interior of said air heating chamber, said auxiliary flue beingarranged to receive naturally descending cold air present in saidhorizontal portion of the mother flue and convey such descending coldair into said air heating chamber whereby the cold air in saidhorizontal portion is automatically evacuated therefrom when said stovemember is first fired and heated air first starts to move outwardly fromsaid chamber and through said mother flue, said lower end of saidauxiliary flue being arranged in heat exchange relation with said stovemember whereby additional heated air is produced in said lower end ofthe auxiliary flue as soon as full firing of the stove member isaccomplished, said additional heated air then rising through saidauxiliary flue and entering said mother flue so as to augment the heatedair therein, said lower end of the auxiliary flue having attachedthereto, a trap comprising a box having a portion arranged through anopening in the side wall of said casing member and extending toward saidstove member, the radially inward end of said portion of the box beingclosely spaced from the side of said stove member and open to pass coldair into said chamber against the side of said stove member and receiveheated air from said chamber from the hot side of said stove member,said lower end of the auxiliary flue entering the topof a portion ofsaid box which extends outwardly of said casing member.

9. A hot air furnace including a stove spacedly enclosed by a casingdefining an air heating chamber, said chamber having an unheated airinlet in its lower part and a heated air outlet in its upper part towhich outlet a main heated air flue is connected and leads away fromsaid furnace to deliver heated air to an enclosure to be heated, meansconnected between an outward part of said main flue and leadingdownwardly and connected to a lower part of said casing andcommunicating with the interior of said chamber and having a portionclose to and in heat exchange relation to said stove, said means beingarranged to receive naturally descending cold air present in said mainflue and convey the same into said lower part of said chamber while thestove is first being fired and heated air starts outwardly in said mainflue, said portion of said 5 means which is in heat exchange relation tosaid stove being arranged to be heated by said stove as the stovebecomes hot whereby heated air will be caused to rise and be conveyed bysaid means to said main flue to augment the heated air in said mainflue.

JAMES Z. ANDERSON.

